Expand description
§Attack, Decay, Sustain, Release generator
§Acronyms used:
ADSR: Attack Decay Sustain Release generatorLUT: Look Up TableDDS: Direct Digital Synthesis
ADSRs are a standard component of most analog synthesizers, used to dynamically modulate various parameters of synthesizers, most commonly loudness, timbre, or pitch.
This ADSR simulates the RC curves typically found in analog ADSRs, where the attack curve is a truncated up-going convex RC curve, and the decay and release curves are down-going concave RC curves.
This ADSR has four variable input parameters:
- Attack time
- Decay time
- Sustain level
- Release time
This ADSR responds to two types of time based events:
- Gate On events initiate an attack phase
- Gate Off events initiate a release phase
This ADSR has a single output:
- The current sample of the ADSR waveform in the range [0.0, 1.0].
A Phase-Accumulator and Look-Up-Table (LUT) approach is used. This is known as “Direct Digital Synthesis”, or DDS.
LUTs are used to store the Attack and Decay curves for the ADSRs. These curves simulate the typical resistor/capacitor time constant curves used in analog ADSRs.
Structs§
- Adsr
- An ADSR envelope generator is represented here
- Sustain
Level - A sustain level in the range
[0.0, 1.0]is represented here - Time
Period - A time period in seconds is represented here
Enums§
Constants§
- MAX_
TIME_ PERIOD_ SEC - The maximum time period for an ADSR state period
- MIN_
TIME_ PERIOD_ SEC - The minimum time period for an ADSR state period